Angier, who only ever cared about the glory of wowing an audience, went to more terrible extremes. In his version of "Transported Man," he created a double of himself every time he used Tesla's machine, and he rigged the trapdoor to drown the one onstage. He never knew if he would be the Prestige or the man in the box. The room where the machine is being kept is filled with water tanks, all of which hold a drowned double of Angier for every time he performed the trick.
Spoiler alert
From http://www.imdb.com/title/tt0482571/synopsis
Angier, who only ever cared about the glory of wowing an audience, went to more terrible extremes. In his version of "Transported Man," he created a double of himself every time he used Tesla's machine, and he rigged the trapdoor to drown the one onstage. He never knew if he would be the Prestige or the man in the box. The room where the machine is being kept is filled with water tanks, all of which hold a drowned double of Angier for every time he performed the trick.